One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(9,10,15,17)(11,16,12,14)(13,21,22,18)(19,24,20,23)(25,26)(27,33)(28,30)(29,39)(31,34)(32,35)(36,40)(37,38)(1,2)(3,6)(4,7)(5,8)(9,11,15,12)(10,16,17,14)(13,19,22,20)(18,23,21,24)(25,27,32,29)(26,33,35,39)(28,38,31,36)(30,37,34,40)(10,17)(11,12)(13,22)(23,24)(25,28,32,31)(26,30,35,34)(27,36,29,38)(33,40,39,37)(1,3,5,4)(2,6,8,7)(9,12,15,11)(10,16,17,14)(13,20,22,19)(18,23,21,24)(25,29,32,27)(26,33,35,39)(28,38,31,36)(30,40,34,37)(1,4,5,3)(2,7,8,6)(9,13,15,22)(10,18,17,21)(11,19,12,20)(14,24,16,23)(25,30)(26,28)(27,37)(29,40)(31,35)(32,34)(33,38)(36,39)(9,14,15,16)(10,11,17,12)(13,23,22,24)(18,20,21,19)(25,31,32,28)(26,34,35,30)(27,38,29,36)(33,37,39,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.